Call coverage is a feature in business communication systems wherein an uncompleted call to a principal's telephone is routed to an alternate destination by the business communication system. The call can be uncompleted for a number of reasons: the principal's telephone is busy, the principal does not answer the telephone call, the principal has activated a call forwarding feature on the principal's telephone. The business communication system responds to an uncompleted call by selecting an alternate destination for the call and connecting the calling party to this alternate destination. There are a number of possible alternate destinations that can be selected by the business communication system. These call coverage points are either defined by the principal or programmed into the business communicatoin system by the system administrator.
One common call coverage arrangement is known as principal-secretary. This is the situation where the principal's phone is covered by a secretary and all calls that are not completed to the principal's telephone are routed by the business communication system to the secretary for handling. Another call coverage arrangement is known as message center which comprises a centralized group of message center operators who receive calls redirected by the business communication system from any one of a number of principals. The message center feature has provisions for the business communication system to provide an indication to the message center attendant of the identity of the principal whose call is being rerouted. Another call coverage arrangement is commonly referred to as voice mail which system provides an audio prompt to the calling party so the calling party can leave a recorded voice message on the voice mail system. The voice mail system encodes and stores the message provided by the calling party for later retrieval by the principal. Still another call coverage arrangement is leave word calling where a calling party served by the same business communication system as the principal has a digital telephone station set which is equipped with the leave word calling feature. When the calling party realizes that the principal is not answering the call or that the principal's telephone is busy, the calling party can press the leave-word calling feature button on the calling party's telephone station set. The business communication system responds to the operation of the leave-word calling button by storing a predefined message identifying the calling party for later retrieval by the principal.
It is not uncommon for a principal to have more than one of the above mentioned call coverage arrangements. The problem with this arrangement is that the principal is required to retrieve messages from a number of different call coverage systems and the messages so retrieved are typically not consistent in informational content. This disparity in service and the requirement that the principal sequentially retrieve messages from a number of call coverage systems is inconvenient and ineffecient for the principal.